Liquid storage for facility chemical supply system

ABSTRACT

A lithography includes a storage tank that stores process chemical fluid, an anti-collision frame, and an integrated sensor assembly. The storage tank includes a dispensing port positioned at a lowest part of the storage tank in a gravity direction. The anti-collision frame is coupled to the storage tank. An integrated sensor assembly is disposed on at least one of the anti-collision frame and the storage tank to measure a variation in fluid quality in response to fluid quality measurement of fluid.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/955,854 filed on Dec. 31, 2019, the entire contents of which areincorporated herein by reference.

BACKGROUND

In semiconductor applications, chemical reagents and compositions arerequired to be supplied in a high purity state, and specializedpackaging or storage design has been developed to ensure that thesupplied material is maintained in a pure and suitable form, throughoutthe package fill, storage, transport, and ultimate dispensingoperations.

Maintaining a high purity is particularly important for thesemiconductor applications, because any contaminants in the packagedmaterial, and/or any ingress of environmental contaminants to thecontained material in the package, may adversely affect thesemiconductor device products that are manufactured with such liquids orliquid-containing compositions, rendering the semiconductor deviceproducts deficient or even useless for their intended use. As such, manytypes of high-purity packaging have been developed for liquids andliquid-containing compositions used in semiconductor devicemanufacturing, such as photoresists, etchants, chemical vapor depositionreagents, solvents, wafer and tool cleaning formulations, chemicalmechanical polishing compositions (e.g., slurry), etc.

With respect to the high-purity packaging, conventional packaging suchas containers or tanks have some issues. For example, liquid remains atthe bottom of tanks and cannot be cleaned thoroughly, and an efficientcleaning process of the tank is difficult. Therefore, there is a growingneed for the high-purity packaging that minimizes residual chemicals andmaintain a pure and suitable form, throughout the package fill, storage,transport, and ultimate dispensing operations.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 shows a properties of tanks in accordance with some embodimentsof the present disclosure.

FIG. 2 shows a schematic view of an apparatus for an integrated storagetank system constructed in accordance with some embodiments of thepresent disclosure.

FIG. 3 shows a schematic view of a storage tank in accordance with someembodiments of the present disclosure.

FIG. 4 shows a schematic view of another storage tank in accordance withsome embodiments of the present disclosure.

FIGS. 5 and 6 illustrate a schematic view of an exemplary integratedsensor assembly according to the present disclosure.

FIG. 7 shows a schematic of a feedback control system for controllingfluid according to some embodiments of the present disclosure.

FIG. 8 shows a flow chart of a method of controlling a feedback controlsystem of an semiconductor process chemical fluid according to anembodiment of the disclosure.

FIG. 9 illustrates a method of cleaning the storage tank according to anembodiment of the disclosure.

FIGS. 10A and 10B illustrate a configuration of the controller inaccordance with some embodiments of the disclosure.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

Semiconductor processes, such as photolithography and wet etch andclean, have become more metal sensitive at advanced process nodes. Influoropolymer delivery systems, metals leaching from material incomponents such as perfluoroalkoxy alkane (PFA) tubing, valves, andpurifiers impact device yield. It can take months for metal contaminantsto leach out of materials. Manufacturers are working to reducecontamination by researching ultraclean PFA materials, performing metalsextraction testing on products, and optimizing processes to reducecontamination. Many invest in identifying where impurities may beintroduced, and take corrective actions to prevent them.

Drum-shaped tanks and Intermediate Bulk Container (IBC) totes arecommonly used in semiconductor processing applications. However, thesetypes of tanks have some issues. For example, liquid remains at thebottom of tanks and cannot be used thoroughly, and an efficient cleaningprocess of the tank is difficult.

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

During a semiconductor manufacturing process, various types of liquidare used. The liquid used in the semiconductor manufacturing processincludes, for example, water, aqueous solutions, acid (HF, buffered HF,HCl, H₂SO₄, etc), alkaline (KOH, TMAH, etc), photo resist, organicsolvent (IPA, etc), H₂O₂, aqueous ammonia solution, and so on. By way ofexample and without limitation, propylene glycol methyl ether (PGME),propylene glycol methyl ether acetate (PGMEA), n-butyl acetate, isoamylacetate, dimethyl sulfoxide, gamma-butyrolactone, 2-heptanol, andisobutyl propionate are also used in some embodiments.

FIG. 1 shows properties of tanks in accordance with some embodiments ofthe present disclosure. As shown in FIG. 1 , the drum-shaped tanks storeabout 200 liters of liquid, the Intermediate Bulk Container (IBC) totestores about 1,000 liters of liquid. Compared to the drum-shaped tank,the IBC tote is harder to clean. Both the drum-shaped tank and the IBCtotes have feed inlets and outlets on the top side of them. It isdifficult to determine the liquid level in both drum-shaped tanks andIBC totes, and recycling the tanks and totes are difficult because theyare difficult to clean.

To remedy the remaining liquid volume problem, numerous designs of thecontainers have been proposed to facilitate emptying and refilling thetanks with liquid to reduce the remaining liquid volume within thestorage tank.

Embodiments disclosed herein provide a liquid packaging to replace thetraditional drum-shaped tank or the IBC tote. Liquid packagingembodiments of the present disclosure provide a liquid holding volumeranging from about 800 liters that are easier to clean and flush thandrum-shaped tanks or IBC totes. The packaging according to theembodiments of the present disclosure is made of a polyethylene (PE),such as high-molecular weight polyethylene (HMWPE) or ultra-highmolecular weight polyethylene (UHMWPE), or a fluoropolymer, such aspolytetrafluoroethylene (PTFE), or has an inner wall coated with PE orPTFE. Embodiments of the packaging includes from about 1 to about 5connectors located at top and bottom sides of the packaging in someembodiments. Embodiments of the packaging include an easy access todetermine the liquid level, good recycle cleanness, and a remainingvolume of the liquid ranging from about 0 to about 5 liters when thepackaging is “empty.”.

FIG. 2 schematically illustrates an integrated storage tank system 1000constructed in accordance with an embodiment of the present disclosure.As shown in FIG. 2 , the integrated storage tank system 1000 includes astorage tank 1020, an anti-collision frame 1030 securely holding thestorage tank 1020, and an integrated sensor assembly 1050. The storagetank 1020 include liquid inlet ports 1022 and a liquid dispensing port1024. The liquid inlet ports 1022 are configured to couple with a fluidsupply container, and the liquid dispensing port 1024 is configured forcoupling to a process tool. The integrated sensor assembly 1050 isdisposed on or adjacent to the anti-collision frame 1030 and the storagetank 1020. The integrated storage tank system 1000 further includes acontroller 1210 that is configured to communicate with the chemicalsupply system 1010 and the integrated sensor assembly 1050 for measuringthe fluid stored in the storage tank 1020.

The liquid inlet ports 1022 and/or the liquid dispensing port 1024 arefluidly coupled to a fluid dispensing system that includes valves 1012,a pump 1014, and a compressor 1016 that are configured to deliver thefluid to a next process tool. In some embodiments, the fluid dispensingsystem is configured to control the pump by adjusting a speed of thepump to maintain the desired flow rate. In some embodiments, the fluiddispensing system is configured to control the pump by adjusting a speedof the pump to maintain the desired fluid pressure.

As shown in FIG. 2 , in one embodiment of the present disclosure, thestorage tank 1020 includes the liquid dispensing port 1024 positionedlower than the liquid inlet ports 1022 in the gravity direction. In someembodiments, the liquid dispensing port 1024 is positioned at a lowestpart of the storage tank 1020. The shape of the liquid inlet ports 1022is different from the shape of the liquid dispensing port 1024 in someembodiments. The size (e.g., diameter) of the liquid inlet ports 1022 isdifferent from the size of the liquid dispensing port 1024 in someembodiments. In some embodiments, the size of the liquid inlet ports1022 is larger than or smaller than the size of the liquid dispensingport 1024. The number of liquid inlet ports 1022 is the same as ordifferent from the number of the liquid dispensing ports 1024 in someembodiments.

In a dispensing operation involving such a lower liquid dispensing port1024, the liquid is dispensed from the liquid dispensing port 1024 byconnecting a dispensing assembly 1062 to the liquid dispensing port1024. After the dispensing assembly 1062 is coupled to the liquiddispensing port 1024, fluid pressure is applied on the liquid dispensingport 1024, so that it forces the liquid to flow through the dispensingassembly 1062 for discharge to associated flow circuitry to an end-usesite. Alternatively, a negative pressure can be applied to the liquiddispensing port 1024 or to the dispensing assembly 1062 connectedthereto, in order to draw the liquid out of the storage tank 1020. Insome embodiments, the liquid dispensing port 1024 is used with thestorage tank 1020 for draining purpose. In other embodiments, the liquiddispensing port 1024 is used with the storage tank 1020 for cleaningpurpose.

FIG. 3 schematically illustrates a storage tank 1020 in accordance withan embodiment of the present disclosure. The storage tank 1020 includesa side wall 12, a first end 14, and a second end 16. As shown in FIG. 3, the first end 14 includes one or more liquid inlet ports 1022 disposedon the first end 14, and the second end 16 is generally opposed to thefirst end 14 of the storage tank 1020. The side wall 12 has acylindrical shape and extends between the first end 14 and second end16, such that the first end 14, second end 16, and side wall 12generally define a storage tank exterior 18. The anti-collision frame1030 is configured to securely fasten the storage tank 1020 based on thestorage tank exterior 18. In some embodiments, a top profile 22 of thestorage tank exterior 18 in the first end 14 is the same with a bottomprofile 24 of the storage tank exterior 18 in the second end 16. In someembodiments, the top profile 22 of the storage tank exterior 18 in thefirst end 14 is different from the bottom profile 24 of the storage tankexterior 18 in the second end 16.

FIG. 4 shows a schematic view of another storage tank in accordance withsome embodiments of the present disclosure. As shown in FIG. 4 , in someembodiments, the storage tank 1020 includes a frustoconical base 1029 inthe second end 16 including a larger radius of curvature R1 near thedispensing port 1024 than the radius of curvature R2 near the side wall12. The second end 16 of the storage tank 1020 has the radius ofcurvature R1 ranging from about 50 mm to about 2000 mm. In someembodiments, the radius of the curvature R2 ranges from about 50 mm toabout 2000 mm among 50 mm, 100 mm, 200 mm, 500 mm, 1000 mm, 2000 mminclusive of any combination of radius therebetween. In such anembodiment, the storage tank 1020 is configured to slow down thedispensing rate through the liquid dispensing port 1024 and to reducethe risk of electrostatic discharge around the storage tank 1020. Thelarger radius of curvature provides a more gradual slope to the tankbottom. Therefore, the flow along the tank bottom will be slower than ifthe radius of curvature had a steeper curve or grade.

The volume of the storage tank 1020 is in a range from about 100 litersto about 2000 liters, and can accommodate from about 1 to 10,000 litersof liquid in some embodiments. The volume of the storage tank 1020 is ina range from about 500 liters to about 1000 liters, or in a range fromabout 4 to 8,000 liters (e.g., 6,000 liters) in other embodiments. Thecorners are rounded in some embodiments (e.g. R2, R3). The bottom ofstorage tank exterior 18 of the storage tank 1020 has a corner having aradius of curvature R2 ranging from about 50 mm to about 2000 mm. Insome embodiments, the radius of the curvature R2 ranges from about 50 mmto about 2000 mm among 1 mm, 2 mm, 5 mm, 10 mm, 20 mm, 50 mm, 100 mm,200 mm, 500 mm, 1000 mm, 2000 mm inclusive of any combination of radiustherebetween. The diameter of the storage tank 1020 is in a range fromabout 1000 mm to about 1500 mm and a height of the storage tank 1020 isin a range from about 1000 mm to about 1500 mm. In some embodiments, thestorage tank 1020 has a cylindrical body portion and the frustoconicalbase 1029, which are smoothly connected with a rounded transitionportion.

In some embodiments, the storage tank 1020 is made of one or more of apolyethylene (PE), a fluoropolymer, including a polytetrafluoroethylene(PTFE), and a stainless steel, including SS316L. In the SS316L stainlesssteel, the addition of 2% molybdenum provides greater resistance toacids and localized corrosion caused by chloride ions. Low-carbonstainless steels, such as 316L, have carbon contents below 0.03% and areused to avoid corrosion problems. When stainless steel or other metallicmaterials are used, the inner wall of the storage tank is coated with PEor PTFE in some embodiments.

In some embodiment, the storage tank 1020 includes an inner surface thatis coated with a coating material, such as PE or PTFE, in someembodiments. In some embodiment, the storage tank 1020 further includesa liner (not shown) disposed in the storage tank having an interiorvolume. In such an embodiment, the liner is retained in a fixed positionin the interior volume to maintain the high purity of the liquid medium.In some embodiments, the liner is made of PE or PTFE.

In some embodiments, the storage tank 1020 further includes a built-indip tube 1032 immersed in the contained liquid and a return tube 1034.In some embodiments, the built-in dip tube 1032 is configured to allowvisual inspection. In other embodiments, the built-in dip tube 1032 isconfigured to improve circulation and/or prevent chemical splash. Thebuilt-in dip tube 1032 and the return tube 1034 are made of a chemicallyinert material that can withstand corrosive chemicals. In certainembodiments, the built-in dip tube 1032 is made of stainless steel 316LEP to reduce maintenance costs and minimize spills across a wide rangeof temperatures and chemistries. In an alternative embodiments, thebuilt-in dip tube 1032 is made of PFA or PTFE. In some embodiments, thestorage tank 1020 may be connected with recirculation tanks, mixing orstorage vessels and other storage tanks to meet semiconductor processneeds.

FIGS. 5 and 6 illustrate an exemplary integrated sensor assembly 1050according to the present disclosure. In some embodiments, the integratedsensor assembly 1050 includes a liquid gauge 1051 (shown in FIG. 6 ) andanalysis tubing 1052, 1054 removably mounted in the anti-collision frame1030. The tubing provides a liquid pathway to and from the tank, so thatliquid can flow into the integrated sensor assembly. As shown in FIG. 5, in some embodiments, an upstream analysis tubing 1052 is fluidlycoupled to the liquid inlet ports 1022 and a downstream tubing 1054 isfluidly coupled to the liquid dispensing port 1024.

In some embodiments, the integrated sensor assembly 1050 includes aliquid level sensor 1056. In a certain embodiment, the liquid levelsensor 1056 further includes a high liquid level sensor 1056 a in theupper portion of the storage tank 1020 and a low liquid level sensor1056 b in the lower portion of the storage tank 1020. In someembodiments, the low liquid level sensor 1056 b is operatively coupledwith the liquid discharge valve, and are operatively coupled with thefluidic element controller 1059 to further modulate the liquid dischargevalve, to avoid shortage of the liquid and to discharge from the storagetank 1020 for use in tracking liquid usage. The high liquid level sensoris configured to monitor the liquid level to prevent overfilling of thetank.

As shown in FIG. 6 , in some embodiments, the anti-collision frame 1030further includes a plurality of grounding connections 1036 and a staticelectricity detector 1038 configured to minimize the risk of the storagetank 1020 accumulating static charge therein. In some embodiments, theanti-collision frame 1030 is arranged such that the liquid dispensingport 1024 of the storage tank 1020 may not be opened unless theplurality of grounding connections 1036 are properly installed. Thisfeature prevents danger when flammable liquids are stored in the storagetank 1020. In some embodiments, the anti-collision frame 1030 may bearranged such that the liquid dispensing port 1024 of the storage tank1020 may not be opened unless a relative humidity is higher than apredefined threshold. In some embodiments, the static electricitydetector 1038 are operatively coupled with the fluidic elementcontroller 1059 and/or controller 1210 to further monitor, record andgenerate an alarm in connection with the static electricity adjacent tothe liquid discharge valve for use in tracking liquid usage. In someembodiments, based on the alarm generated, the controller 1210 furthersends a notification to a first external device associated with afluidic element controller 1059 and a second external device associatedwith the next process tool.

In some embodiments, the integrated sensor assembly 1050 includes atemperature sensor 1058. As shown in FIG. 6 , the temperature sensor1058 further includes a first temperature sensor 1058 a in the upperportion of the storage tank 1020 and a second temperature sensor 1058 bin the lower portion of the storage tank 1020. In some embodiments, thesecond temperature sensor 1058 b measures the temperature adjacent tothe liquid discharge valve, and is operatively coupled with the fluidicelement controller 1059 to further monitor, record and generate an alarmin connection with the temperature adjacent to the liquid dischargevalve for use in tracking liquid usage. In some embodiments, based onthe alarm generated, the controller 1210 further sends a notification toa first external device associated with a fluidic element controller1059 and a second external device associated with the next process tool.

In some embodiments, the storage tank 1020 further includesquick-fitting connectors to ensure the appropriate connections preventpossible unsafe chemical mixing of fluids, for example, an incompatiblenew solvent and the old solvent. FIG. 6 shows schematic views of thestorage tank 1020 with a quick-fitting mechanism 1057 according tovarious embodiments of the present disclosure. In some embodiments, amating connector includes a quick-fitting portion to mate with theliquid inlet ports 1022 and to engage the quick-fitting portion with amounting side of the liquid inlet ports 1022, thereby enabling quick,easy, and secure connection between the quick-fitting mechanism and theliquid inlet ports 1022. In some embodiments, the liquid inlet ports1022 include an inclined portion of the quick-fitting portion thatallows easy engagement with the liquid inlet ports 1022.

In some embodiments, the storage tank 1020 includes an ultrasonic liquidlevel sensor that may measure a distance between the ultrasonic liquidlevel sensor and a surface of the process liquid stored in the storagetank 1020. In some embodiments, when the storage tank 1020 is nearempty, the ultrasonic liquid level sensor further sends a notificationbased on the liquid level information indicating that the storage tank1020 is near empty. In some embodiments, based on the generating thenotification, the feedback further sends the notification to a firstexternal device associated with a fluidic element controller 1059 and asecond external device associated with the next process tool.

In some embodiments, the anti-collision frame 1030 further includes agate and a slot configured to receive the storage tank 1020 slidablytherein. In some embodiments, the anti-collision frame 1030 may bearranged such that the gate of the anti-collision frame may not be fullyshut unless the mating connector of the liquid inlet ports 1022 isproperly installed. For example, the anti-collision frame 1030 may bearranged such that the gate of the anti-collision frame will not fullyshut unless the storage tank 1020 is fully inserted into slot 310 (shownin FIG. 6 ) and/or mating connector associated with a the liquid inletports 1022 is properly installed in the anti-collision frame 1030.

Tanks of the present embodiments have much less liquid remaining insidethe tank when the tank is “empty” than conventional drum-shaped tanks orIBC totes. Tanks of the present embodiments inhibit mixing of newsolvent and old solvent. The tank of the present embodiments is easierto clean and more easily dispense liquid than the conventional tanks. Insome embodiment, the storage tank 1020 further includes an agitatoradjacent to the liquid dispensing port 1024, such that the liquid can bestirred by the agitator before the liquid is dispensed from the liquiddispensing port 1024. The agitator is operatively coupled with thefluidic element controller 1059 and/or controller 1210 (see FIG. 7 ) tofurther monitor, record and generate an alarm for use in tracking liquidusage. In some embodiments, the agitator is configured to monitor,record and generate an alarm for use in tracking liquid usage. In someembodiments, based on the alarm generated, the controller 1210 furthersends a notification to a first external device associated with afluidic element controller 1059 and a second external device associatedwith the next process tool.

When liquids are shipped in the container or tank, a gas space isgenerally maintained above the liquid, as a headspace gas, toaccommodate thermal expansion and contraction of the liquid withoutexcessive mechanical strain being placed on the storage tank. As theliquid is agitated during transport and other movement of the package,bubbles can become entrapped in the packaged liquid. If the liquid hashigh viscosity, such bubbles, particularly small ones, can remain in theliquid for a very long time. The use of such fluid analyzers is intendedto monitor the purity of the liquid for its intended purpose.

Additionally, the presence of microbubbles in the liquid may beproblematic from the standpoint of the presence of gas therein. Theentrapped gas may interfere with subsequent processing of the liquid, orit may adversely affect a product manufactured with the liquid, andrender it deficient or even useless for its intended purpose.Accordingly, elimination of bubble formation is important in relation tothe accuracy and reliability of fluid determine for the material, aswell as for efficient processing as well as manufacturing of endproducts using the liquid medium.

In some embodiments, the storage tank 1020 is a pressure vessel designedfor pressurization to allow direct chemical dispensing from the storagetank without the need for pumps.

As shown in FIG. 7 , in some embodiments, a feedback control system 1200is provided for controlling chemical fluid quality based on a rate ofchange in fluid quality generated by a spectrum analyzer 1100. Thespectrum analyzer is configured to monitor certain wavelengths of light,such as infrared (IR) or ultraviolet (UV), to detect the presence ofcertain chemical contaminants in the liquid. In some embodiments, thespectrum analyzer is an optical spectrometer configured to measureproperties of light over a specific portion of the electromagneticspectrum to identify materials. In such embodiments, the measuredvariable is the light's intensity but, in an alternative embodiment, isthe polarization state. In some embodiments, the spectrum analyzer is aliquid chromatograph-mass spectrometer. In such embodiments, liquidchromatography separates mixtures with multiple components, and the massspectrometer provides structural identity of the individual componentswith high molecular specificity and detection sensitivity.

The feedback control system 1200 monitors a rate of change in fluidquality indicated by the analysis from the spectrum analyzer 1100. Insome embodiments, the analysis of the fluid quality is performed by thespectrum analyzer 1100 located adjacent to the storage tank 1020. Insome embodiments, the spectrum analyzer 1100 is located away from thestorage tank 1020. In some embodiments, an analysis for the fluidquality is performed at or adjacent to the liquid dispensing port 1024to monitor the rate of change in the fluid quality. In some embodiments,the analysis of the fluid quality is performed on the next process tool.In some embodiments, the rate of change in the fluid quality isdetermined by the controller 1210 based on the analysis of the fluidquality by the spectrum analyzer 1100. The fluid quality measured by thespectrum analyzer 1100 indicates presence or absence of the fluidadjacent to the liquid dispensing port 1024 in some embodiments. In someembodiments, the fluid quality measured by the spectrum analyzer 1100indicates the purity of the fluid adjacent to the liquid dispensing port1024. In some embodiments, when changes in the fluid quality aredetected by the spectrum analyzer 1100, the controller 1210 of thefeedback control system 1200 performs a pre-determined process based ona value of the fluid quality and/or a changing rate of the fluid qualitymeasured by the spectrum analyzer 1100.

In some embodiments, the spectrum analyzer 1100 includes a logic circuitprogrammed to generate a signal when the detected variation in analysisof the fluid quality is not within an acceptable range. For example, asignal is generated when the detected variation in the analysis of thefluid quality is above a certain threshold value. The threshold value ofvariation in analysis of the fluid quality is, for example, an expectedminimum variation in the analysis of the fluid quality. In someembodiments, the expected minimum variation in the analysis of the fluidquality is determined based an average variation in analysis of thefluid quality for a largest change. In some embodiments, the expectedminimum variation in the analysis of the fluid quality is, for example,one standard deviation or two standard deviations less than the averagevariation in the analysis of the fluid quality determined for thelargest change.

In some embodiments, a variation in the fluid quality measured by thespectrum analyzer 1100 is used as a feedback for adjusting a time delaybetween a subsequent supply and dispensing of the liquid. In someembodiments, a fluidic element controller 1059 is located adjacent tothe anti-collision frame 1030. In some embodiments, a fluidic elementcontroller 1059 is located away from the anti-collision frame 1030. Thefluidic element controller 1059 controls a plurality of fluidic elementssuch as a control valve, a pump, and a compressor. The signal from thefluidic element controller 1059 is used as a feedback for adjusting thetime delay between subsequent process chemical fluid supply anddispensing in some embodiments. In some embodiments, the feedback may beconnected with an actuator to control one of the fluidic elements.

The feedback control system provided in some embodiments further send anotification based on a subsequent quality analysis informationindicating the quality analysis is within the acceptable qualityanalysis range. In some embodiments, the notification includes aspectrum difference between the process chemical fluid supply and thedispensing. In some embodiments, based on the generating thenotification, the feedback further sends the notification to a firstexternal device associated with a fluidic element controller 1059 and asecond external device associated with the next process tool.

FIG. 9 illustrates a method of cleaning the storage tank 1020 accordingto an embodiment of the disclosure. First, a liquid level of thechemical fluid is checked using the liquid level sensor 1056. A qualityof the chemical fluid is then checked using the spectrum analyzer 1100.In a following step, the chemical fluid is circulated along acirculation line 1042. The chemical fluid is then flushed to a flushline 1044. Finally, chemical fluid is filled in the storage tank 1020.

FIGS. 10A and 10B illustrate a configuration of the controller 1210 inaccordance with some embodiments of the disclosure. In some embodiments,a computer system 2000 is used as the controller 1210. In someembodiments, the computer system 2000 performs the functions of thecontroller as set forth above.

FIG. 10A is a schematic view of a computer system. All of or a part ofthe processes, method and/or operations of the foregoing embodiments canbe realized using computer hardware and computer programs executedthereon. In FIG. 10A, a computer system 2000 is provided with a computer2001 including an optical disk read only memory (e.g., CD-ROM orDVD-ROM) drive 2005 and a magnetic disk drive 2006, a keyboard 2002, amouse 2003, and a monitor 2004.

FIG. 10B is a diagram showing an internal configuration of the computersystem 2000. In FIG. 10B, the computer 2001 is provided with, inaddition to the optical disk drive 2005 and the magnetic disk drive2006, one or more processors, such as a micro processing unit (MPU)2011, a ROM 2012 in which a program such as a boot up program is stored,a random access memory (RAM) 2013 that is connected to the MPU 2011 andin which a command of an application program is temporarily stored and atemporary storage area is provided, a hard disk 2014 in which anapplication program, a system program, and data are stored, and a bus2015 that connects the MPU 2011, the ROM 2012, and the like. Note thatthe computer 2001 may include a network card (not shown) for providing aconnection to a LAN.

The program for causing the computer system 2000 to execute thefunctions of an apparatus for controlling the apparatus in the foregoingembodiments may be stored in an optical disk 2021 or a magnetic disk2022, which are inserted into the optical disk drive 2005 or themagnetic disk drive 2006, and transmitted to the hard disk 2014.Alternatively, the program may be transmitted via a network (not shown)to the computer 2001 and stored in the hard disk 2014. At the time ofexecution, the program is loaded into the RAM 2013. The program may beloaded from the optical disk 2021 or the magnetic disk 2022, or directlyfrom a network. The program does not necessarily have to include, forexample, an operating system (OS) or a third party program to cause thecomputer 2001 to execute the functions of the controller 1210 in theforegoing embodiments. The program may only include a command portion tocall an appropriate function (module) in a controlled mode and obtaindesired results.

The integrated storage tank system and the feedback control system forcontrolling chemical fluid quality in accordance with embodiments of thepresent disclosure provide a high-purity packaging that minimizesresidual chemicals, and maintains a pure and suitable form, throughoutthe package fill, storage, transport, and ultimate dispensingoperations.

An embodiment of the disclosure is a liquid supply system that includesa storage tank, an anti-collision frame, and an integrated sensorassembly. The storage tank stores a process chemical fluid and includesa dispensing port that is positioned at a lowest part of the storagetank in a gravity direction. The anti-collision frame is coupled to thestorage tank. The integrated sensor assembly is disposed on at least oneof the anti-collision frame and the storage tank to measure a variationin fluid quality in response to a fluid quality measurement of fluid. Insome embodiments, the storage tank includes a frustoconical base. Insome embodiments, the liquid supply system further comprises a feedbackcontroller coupled to the integrated sensor assembly and one or moreadjustable fluidic elements controlling supply and dispense of theprocess chemical fluid associated with the liquid supply system. In someembodiments, the feedback controller is configured to adjust one or moreparameters of the process chemical fluid and the adjustable fluidicelement based on a variation in output of the integrated sensor assemblygenerated by the fluid. In some embodiments, the feedback controller isconfigured to determine whether a variation in fluid quality measurementof the fluid is within an acceptable range. In some embodiments, inresponse to the variation in fluid quality measurement that is notwithin the acceptable range, the feedback controller automaticallyadjusts a configurable parameter of the fluid stored in a storage tank.In some embodiments, the feedback controller sends a notification basedon a fluid quality measurement information when a rate of change influid quality generated by a spectrum analyzer is greater than athreshold.

Another embodiment of the disclosure is a liquid supply system thatincludes a storage tank, an anti-collision frame, an integrated sensorassembly and a feedback controller. The storage tank stores processchemical fluid, and includes a liquid dispensing port positioned at alowest part of the storage tank in a gravity direction. Theanti-collision frame is coupled to the storage tank. The integratedsensor assembly is disposed on at least one of the anti-collision frameand the storage tank. The feedback controller is coupled to theintegrated sensor assembly and one or more of a process supply source,and fluidic control elements controlling supply and dispense of theprocess chemical fluid associated with the liquid supply system. Thefeedback controller is configured to adjust one or more parameters ofthe process chemical fluid and the fluidic control elements controllingthe supply and the dispense of the process chemical fluid in response toa measurement result of the integrated sensor assembly. In someembodiments, the storage tank includes a frustoconical base. In someembodiments, the storage tank includes a larger radius of curvature nearthe dispensing port than a radius of curvature near a side wall. In someembodiments, the storage tank has same top and bottom exterior profiles.In some embodiments, the storage tank has different top and bottomexterior profiles. In some embodiments, the fluidic control elements areliquid discharge valves. In some embodiments, the storage tank includesa plurality of grounding connections and a static electricity detector.

Yet another embodiment of the disclosure is a method of controlling afeedback control system of a semiconductor process chemical fluid. Themethod includes measuring a configurable parameter of the semiconductorprocess chemical fluid stored in a storage tank. Then, a fluid qualitymeasurement of fluid is performed by a spectrum analyzer. Subsequently,a variation in fluid quality measurement of the fluid is determinedwhether the variation is within an acceptable range. In response to avariation in fluid quality measurement that is not within the acceptablerange of variation in fluid quality measurement, the configurableparameter of the semiconductor process chemical fluid is automaticallyadjusted to set the variation in fluid quality measurement of the fluidwithin the acceptable range. In some embodiments, the feedback controlsystem further generate a notification based on a new fluid qualitymeasurement information indicating the fluid quality measurement iswithin the acceptable fluid quality measurement range. In someembodiments, the feedback control system further send a notification toa first external device associated with a fluidic element controller anda second external device associated with a next process tool. In someembodiments, after measuring a configurable parameter of thesemiconductor process chemical fluid stored in a storage tank, thefeedback control system further measure static electricity measured by astatic electricity detector adjacent to a liquid discharge valve. Insome embodiments, the feedback control system further adjust time delaybetween subsequent process chemical fluid supply and dispensing of thefluid. In some embodiments, the feedback control system further send thenotification to a first external device associated with an adjustablefluidic element controller and a second external device associated witha liquid supply system.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A liquid supply system, comprising: a storagetank for storing a process chemical fluid, the storage tank including adispensing port positioned at a lowest part of the storage tank in agravity direction; an anti-collision frame coupled to the storage tank;and a spectrum analyzer located adjacent to the dispensing port of thestorage tank to measure a variation in fluid quality in response to afluid quality measurement of fluid, wherein a time delay betweensubsequent process chemical fluid supply and dispensing of the fluid isadjusted based on the variation in fluid quality measured by thespectrum analyzer; a feedback controller coupled to the spectrumanalyzer and one or more valves controlling supply and dispense of theprocess chemical fluid associated with the liquid supply system; whereinthe feedback controller is configured to adjust one or more parametersof the process chemical fluid and the valves based on a variation inoutput of the spectrum analyzer generated by the fluid.
 2. The liquidsupply system of claim 1, wherein the storage tank includes afrustoconical base.
 3. The liquid supply system of claim 1, wherein thefeedback controller is configured to determine whether the variation influid quality is within an acceptable range.
 4. The liquid supply systemof claim 1, wherein the feedback controller, in response to thevariation in fluid quality that is not within the acceptable range,automatically adjusts a configurable parameter of the fluid stored inthe storage tank.
 5. The liquid supply system of claim 1, wherein thefeedback controller sends a notification based on a fluid qualitymeasurement information when a rate of change in fluid quality generatedby the spectrum analyzer is greater than a threshold.
 6. A liquid supplysystem, comprising: a storage tank storing process chemical fluid, thestorage tank including a liquid dispensing port positioned at a lowestpart of the storage tank in a gravity direction; an anti-collision framecoupled to the storage tank; a spectrum analyzer located adjacent to theliquid dispensing port of the storage tank to measure a variation influid quality; and a feedback controller coupled to the spectrumanalyzer and one or more of a process supply source, and fluidic controlelements controlling supply and dispense of the process chemical fluidassociated with the liquid supply system, wherein the feedbackcontroller is configured to adjust a time delay between subsequentprocess chemical fluid supply and dispensing of the fluid based on thevariation in fluid quality measured by the spectrum analyzer; whereinthe feedback controller is configured to adjust one or more parametersof the process chemical fluid and the fluidic control elements based ona variation in output of the spectrum analyzer generated by the processchemical fluid.
 7. The liquid supply system of claim 6, wherein thestorage tank includes a frustoconical base.
 8. The liquid supply systemof claim 6, wherein the storage tank includes a larger radius ofcurvature near the dispensing port than a radius of curvature near aside wall.
 9. The liquid supply system of claim 6, wherein the storagetank has same top and bottom exterior profiles.
 10. The liquid supplysystem of claim 6, wherein the storage tank has different top and bottomexterior profiles.
 11. The liquid supply system of claim 6, wherein thefluidic control elements are liquid discharge valves.
 12. The liquidsupply system of claim 9, wherein the storage tank includes a pluralityof grounding connections and a static electricity detector.
 13. Afeedback control system of a liquid supply system, the liquid supplysystem including a storage tank for storing a process chemical fluid,the feedback control system comprising: a spectrum analyzer locatedadjacent to a dispensing port of the storage tank to measure a variationin fluid quality in response to a fluid quality measurement of fluid;and a feedback controller coupled to the spectrum analyzer and anadjustable fluidic element controlling supply and dispense of theprocess chemical fluid, wherein the feedback controller is configured toadjust a time delay between subsequent process chemical fluid supply anddispensing of the fluid based on the variation in fluid quality measuredby the spectrum analyzer; wherein the liquid supply system furthercomprises an anti-collision frame coupled to the storage tank, andwherein the spectrum analyzer is disposed on the anti-collision frame tomeasure the variation in fluid quality in response to the fluid qualitymeasurement of fluid; wherein the feedback controller is configured toadjust one or more parameters of the process chemical fluid and theadjustable fluidic element based on a variation in output of thespectrum analyzer generated by the fluid.
 14. The feedback controlsystem of claim 13, wherein the storage tank includes a dispensing portpositioned at a lowest part of the storage tank in a gravity direction.15. The feedback control system of claim 13, wherein the feedbackcontroller is configured to determine whether the variation in fluidquality is within an acceptable range.
 16. The feedback control systemof claim 15, wherein the feedback controller, in response to thevariation in fluid quality that is not within the acceptable range,automatically adjusts a configurable parameter of the fluid stored inthe storage tank.